Non-conventional antiphospholipid antibodies in patients with clinical obstetrical APS: Prevalence and treatment efficacy in pregnancies

Semin Arthritis Rheum. 2016 Oct;46(2):232-237. doi: 10.1016/j.semarthrit.2016.05.006. Epub 2016 May 25.

Abstract

Objectives: To describe the prevalence of non-conventional APL in patients with obstetrical APS without conventional APL and the impact of treatment on pregnancy outcome.

Methods: Patients with clinical obstetrical criteria were tested for anti-phosphatidylethanolamine (aPE) IgG/M, anti-prothrombin/phosphatidylserine (anti-PS/PT) IgG/M, and anti-annexin V IgG. Pregnancy losses rates were compared between APS, non-conventional APS, and non-APL and in untreated pregnancies to treated ones for each group.

Results: Using the cutoffs (ROC), 65/96 (68%) patients have been considered as non-conventional APS and compared to 83 APS and 31 patients without APL. The obstetrical history in non-conventional APS did not differ in comparison to confirmed APS. The frequencies of anti-annexin V IgG antibodies tended to be more frequent in non-conventional APS (88% versus 73%; p = 0.06), and those of anti-PE IgG and M were similar. The anti-PS/PT IgG and M antibodies were more frequent in confirmed APS than in non-conventional APS (63% and 37% versus 4% and 5%, respectively, p < 0.0001). Overall, 261 pregnancies in patients with non-conventional APS were compared with 81 pregnancies of confirmed APS and 132 pregnancies from non-APL group. Out of 474, 136 (29%) patients have been treated during pregnancies, and treatment significantly increased the rate of live birth (26% in untreated versus 72% in treated pregnancies, p < 0.0001). In univariate analyses, treatment effect on pregnancy losses was similar in patients with APS and non-conventional APS, with odds ratio at 3.3 (95% CI: 1.8-6.1) and 6.9 (95% CI: 3.9-12.3) (p = 0.49) and significantly more important for the 2 APS groups pooled versus non-APL group [OR at 1.9 (95% CI: 1.1-3.5) for non-APL group versus 5.3 (95% CI: 3.5-8.1) for APS groups, p = 0.0025].

Conclusion: In this study, 68% of patients with clinical criteria for obstetrical APS seronegative for conventional APL have non-conventional APL. These patients have a significant decrement of pregnancy losses if they receive treatment for APS during their pregnancy.

Keywords: Antiphospholipid syndrome; Non-conventional antiphospholipids; Obstetrical complications; Pregnancies treatment.

MeSH terms

  • Adult
  • Antibodies, Antiphospholipid*
  • Anticoagulants / therapeutic use
  • Antiphospholipid Syndrome / drug therapy
  • Antiphospholipid Syndrome / epidemiology
  • Antiphospholipid Syndrome / immunology*
  • Aspirin / therapeutic use
  • Female
  • Heparin, Low-Molecular-Weight / therapeutic use
  • Humans
  • Middle Aged
  • Pregnancy
  • Pregnancy Complications / drug therapy
  • Pregnancy Complications / epidemiology
  • Pregnancy Complications / immunology*
  • Pregnancy Outcome
  • Prevalence
  • Treatment Outcome

Substances

  • Antibodies, Antiphospholipid
  • Anticoagulants
  • Heparin, Low-Molecular-Weight
  • Aspirin